I very much assume the Film Photography Project mixed things up.
I never heard of photographic film being used in dactyloscopy other than taking photographic evidence.
One could imagine using wetted photographic film by lack of adhesive tape as makeshift solution..... But already the stiffness of photographic film will form an obstacle.
Taking the fingerprints directly on film and then using the barrier effect of the finger-grease in development for imaging, makes not much sense either seen the classic technologies.
The classic use of direct positive films was in micrography and as copy films.
My best bet to make a connection to dactyloscopy is, this film was used for fingerprint micrography.
But likely just photographic and adhesive films were mixd up.
To yield a direct positive working film different technics may be employed.